1. Field of the Invention
This invention relates generally to gaskets for providing a seal between parts of an internal combustion engine, and methods of manufacturing the same.
2. Related Art
Gaskets are typically used to establish a gas and fluid tight seal between two parts clamped together, such as a cylinder head and an engine block of an internal combustion engine. Such gaskets oftentimes include a functional layer having an embossment, also referred to as a sealing bead, to facilitate the tight seal. The functional layer with the embossment is compressed, optionally with one or more additional functional layers or distance layers, in effort to establish the gas and fluid tight seal. However, when clamping the gasket between the cylinder head and the engine block, damage can occur to the embossment by over-compression. If the embossment is substantially flattened, the embossment loses its ability to exert a high compression sealing pressure, and fatigue cracks can form in the area of the embossment. Thus, a planar stopper is typically incorporated into the cylinder head gasket to restrict compression of the embossment between the cylinder head and the engine block. The stopper is typically a separate component spaced from the embossment.
Federal-Mogul has introduced high performance cylinder head gaskets including stoppers and high-strength, dynamic embossment technology. An exemplary gasket provided by Federal-Mogul includes a pair of functional layers each including a full embossment. Each full embossment presents a convex surface facing toward the other full embossment. A planar stopper is welded to one of the functional layers adjacent the full embossment. A half embossment, referred to as a Flexstop®, is formed in the other functional layer and is axially aligned with the stopper. The half embossment extends inwardly toward the stopper in the same direction as the full embossment. The half embossment maintains a load on the stopper while under loading and joint dynamics, such as headlift.